Chibata et al. early disclosed a method for producing L-aminoacylase by Aspergillus, which had been applied for industrial mass production [T. Tosa, T. Mori and I. Chibata, Agric. Biol. Chem., 33; 1047-1059 (1969)].
Such a conventional enzyme is composed of at least two subunits, with an optimum pH value of 8.0, and having a 2.5-fold enzyme activation as effected by cobalt ions, which however shows poor specific activity and shows no satisfactory stability, especially for thermal stability.
It is therefore expected to invent a process for making L-aminoacylase by microorganism for improving an activity, stability and other properties of a L-aminoacylase.